The present invention relates to a communication system and connection management server apparatus, which have a dormant management function.
Along with the recent abrupt increase in use of the Internet, such a problem is posed that a dialup connection service cannot be provided because of a shortage of connection capacity of an existing remote access server apparatus (to be referred to as an RAS (Remote Access Server) apparatus hereinafter).
To cope with this problem, a communication system having a dormant function has been proposed, which disconnects a line to a data link activated side apparatus (RAS apparatus) when the operation of the terminal apparatus, i.e., the data link activating side apparatus of the user who uses the Internet is in a sleep mode (this state will be referred to as a dormant state hereinafter) and reconnects the line to the data link activated side apparatus when the data link activating side apparatus resumes the operation (active state).
The dormant function is implemented in accordance with, e.g., MITF (Mobile Internet Access Forum) dialup dormant protocol (ARIB (Association of Radio Industries and Businesses) STD-T78 version 1.0).
In a communication system which employs the above-described MITF dialup dormant protocol, since the resource (to be referred to as a physical resource hereinafter) of a circuit switched network for a given call in a dormant state is released, the problem of the shortage of connection capacity of a RAS apparatus is solved.
However, according to ARIB STD-T78, even in the dormant state, the Internet resource (to be referred to as a logical link resource hereinafter) of the RAS apparatus, which is used to connect the RAS apparatus to a Web server apparatus or Mail server apparatus managed by an ISP (Internet Service Provider), is held without being released. For this reason, if a number of calls in the dormant state are present, a shortage of logical link resource may occur for a new call, resulting in a call loss.